共查询到18条相似文献,搜索用时 78 毫秒
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徐维正 《精细与专用化学品》2006,14(1):26-28
直接甲醇燃料电池是全球当前研发追求的新电源,在电能密度、效率、使用寿命等功能方面占有明显优势,而且不用充电即可连续补充使用。直接甲醇燃料电池潜在应用市场广阔,目前,世界各国的厂商都在全力进行DMFC的研制应用,其中大部分厂商都承诺要在2005年推出自己的产品。 相似文献
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直接甲醇燃料电池的阳极采用甲醇作为燃料,阴极采用纯氧或空气作为氧化剂,具有能量密度高、燃料储存方便、结构简单的优点,有望成为下一代小型电子设备的电源。反应物的浓度对直接甲醇燃料电池的性能、效率和燃料利用率等都有很大的影响,因此对燃料电池中反应物的浓度进行准确测量至关重要。本文综述了直接甲醇燃料电池中反应物浓度的测量方法,主要包括化学测量方法和物理测量方法,并对这些测量方法的优缺点、基本原理及适用范围进行了分析和评述。 相似文献
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直接甲醇燃料电池质子交换膜的发展现状 总被引:1,自引:0,他引:1
直接甲醇燃料电池(DMFC)是20世纪90年代兴起的第六代燃料电池,以其诸多的优点引起人们的广泛关注和研究。其中聚合物电解质膜是DMFC的关键技术,起着隔离阴阳极、质子传输、绝缘电子的作用。它的作用决定着DMFC的输出功率、电池效率、成本及应用前景。本文介绍了已商品化的全氟磺酸膜(Nafion膜)的结构及性能、以及替代膜的国内外发展现状,指出DMFC用膜的研究是21世纪能源研究的重点。 相似文献
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通过浸渍还原法以乙二醇为还原剂制备了石墨烯及石墨烯负载的铂催化剂(Pt/Graphene),通过XRD、SEM、Raman对材料进行了分析,通过电化学测试与Pt黑催化剂对比,试验数据表明:Pt/Graphene比Pt黑催化剂电化学活性面积提高了28%,对甲醇电催化氧化峰电流提高了52%,电化学活性面积和甲醇氧化反应的稳定性均有所提高。 相似文献
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An investigation of scale-up on the response of the direct methanol fuel cell under variable load conditions 总被引:3,自引:0,他引:3
The electrical response of the direct methanol fuel cell, based on solid polymer electrolyte, to variable load is reported. The dynamic power response of the direct methanol fuel cell is of importance particularly when the cell is used for transportation applications. The study reports the dynamic characteristics of a small-scale cell (active area 9 cm2), a large-scale cell (active area 272 cm2), and a three-cell stack. The effect of operating conditions (i.e., flow rate, cathode pressure and solution concentration) on the voltage response is described and the effect of a change of scale is discussed. 相似文献
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T. Schultz U. Krewer T. Vidaković M. Pfafferodt M. Christov K. Sundmacher 《Journal of Applied Electrochemistry》2007,37(1):111-119
The dynamic operating behaviour of the direct methanol fuel cell (DMFC) is governed by several physico-chemical phenomena
which occur simultaneously: double layer charging, electrode kinetics, mass transport inside the porous structures, reactant
distributions in the anode and cathode flowbeds etc. Therefore it is essential to analyse the interactions of these phenomena
in order to fully understand the DMFC. These phenomena were initially analysed independently by systematic experiments and
model formulations. Electrode kinetics were determined by fitting models of varying complexity to electrochemical impedance
spectroscopy (EIS) measurements. Reaction intermediates adsorbed on the catalyst seem to play a key role here. To describe
mass transport across the DMFC a one-dimensional model was formulated applying the generalised Maxwell–Stefan equations for
multi-component mass transport and a Flory–Huggins model for the activities of mobile species inside the membrane (PEM). Also
swelling of the PEM as well as heat production and transport were considered. Finally, the anode flowbed was analysed by observing
flow patterns in different flowbed designs and measuring residence time distributions (RTDs). Detailed CFD models as well
as simpler CSTR network representations were used to compare to the experimental results. Even the simpler models showed good
agreement with the experiments. After these investigations the results were combined: the electrode kinetics model was implemented
in the mass transport model as well as in the CSTR network flowbed model. In both cases, good agreement, even to dynamic experiments,
was obtained. 相似文献
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This research aims at increasing the utilization of platinum-ruthenium alloy (Pt-Ru) catalysts and thus lowering the catalyst
loading in anodes for methanol electrooxidation. The direct methanol fuel cell’s (DMFC) anodic catalysts, Pt-Ru/C, were prepared
by chemical reduction with a reducing agent added in two kinds of solutions under different circumstances. The reducing agent
was added in hot solution with the protection of inert gases or just air, and in cold solution with inert gases. The catalysts
were treated at different temperatures. Their performance was tested by cyclic voltammetry and potentiostatic polarization
by utilizing their inherent powder microelectrode in 0.5 mol/L CH3OH and 0.5 mol/LH2SO4 solution. The structures and micro-surface images of the catalysts were determined and observed by X-ray diffraction and
transmission electron microscopy, respectively. The catalyst prepared in inert gases showed a better catalytic performance
for methanol electrooxidation than that prepared in air. It resulted in a more homogeneous distribution of the Pt-Ru alloy
in carbon. Its size is small, only about 4.5 nm. The catalytic performance is affected by the order of the reducing agent
added. The performance of the catalyst prepared by adding the reductant at constant temperature of the solution is better
than that prepared by adding it in the solution at 0°C and then heating it up to the reducing temperature. The structure of
the catalyst was modified, and there was an increase in the conversion of ruthenium into the alloyed state and an increase
in particle size with the ascension of heat treatment temperature. In addition, the stability of the catalyst was improved
after heat treatment.
Translated from Journal of Harbin Institute of Technology, 2006, 38 (4): 541-545 [译自: 哈尔滨工业大学学报] 相似文献
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A model for the liquid feed, direct methanol fuel cell (DMFC), based on the homogeneous two-phase flow theory and mass conservation equation, which describes the hydraulic behaviour of internally manifolded cell stacks, is presented. The model predicts the pressure drop behaviour of the anode side of an individual DMFC cell and is used to determine the channel depth and width for fast and efficient carbon dioxide removal with minimum pressure drop. The model is used to calculate flow distribution through fuel cell stack internal manifolds. The effect of inlet and outlet manifold diameters on flow distribution is also determined. Two types of manifold design are compared, reverse flow and parallel flow. An iterative numerical scheme is used to solve the differential equations for longitudinal momentum and continuity. 相似文献